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authorAlex Converse <alex.converse@gmail.com>2012-05-02 12:08:03 -0700
committerAlex Converse <alex.converse@gmail.com>2012-05-02 13:06:09 -0700
commitb5da848facd41169283d7bfe568b83bdfa7fc42e (patch)
tree5494e1616c17e92f27548104ac898843b34ac0c8 /libavcodec/motionpixels.c
parent5eec5a79da118170f3cfe185a862783d3fa50abe (diff)
downloadffmpeg-b5da848facd41169283d7bfe568b83bdfa7fc42e.tar.gz
motionpixels: Clip YUV values after applying a gradient.
Prevents illegal reads on truncated and malformed input. CC: libav-stable@libav.org
Diffstat (limited to 'libavcodec/motionpixels.c')
-rw-r--r--libavcodec/motionpixels.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/libavcodec/motionpixels.c b/libavcodec/motionpixels.c
index 6151e6a114..8a3c870986 100644
--- a/libavcodec/motionpixels.c
+++ b/libavcodec/motionpixels.c
@@ -190,10 +190,13 @@ static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
p = mp_get_yuv_from_rgb(mp, x - 1, y);
} else {
p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
+ p.y = av_clip(p.y, 0, 31);
if ((x & 3) == 0) {
if ((y & 3) == 0) {
p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
+ p.v = av_clip(p.v, -32, 31);
p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
+ p.u = av_clip(p.u, -32, 31);
mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
} else {
p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
@@ -217,9 +220,12 @@ static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)
p = mp_get_yuv_from_rgb(mp, 0, y);
} else {
p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
+ p.y = av_clip(p.y, 0, 31);
if ((y & 3) == 0) {
p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
+ p.v = av_clip(p.v, -32, 31);
p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
+ p.u = av_clip(p.u, -32, 31);
}
mp->vpt[y] = p;
mp_set_rgb_from_yuv(mp, 0, y, &p);